This Center Grant research and research training program is concerned with the effects of physical and chemical factors in the environment on biologic systems, with particular emphasis on the health of man. Biologic effects include alteration of function, as well as initiation or aggravation of illness, disability and premature death. Although no disease or effect is excluded from consideration, primary interest focuses on cancer, chronic lung disease of specific or non-specific etiology, and effects on reproductive systems. The general approaches employed in these studies are toxicologic and epidemiologic. Toxicologic approaches include a variety of molecular, biochemical and physiologic methods applied to biologic systems ranging from cells to whole organisms. Epidemiologic methods also cover a wide range, from field studies to analyses of vital records and case-control studies. Environmental factors under study include (a) occupational hazards, with specific interest in carcinogens and pulmonary pathogenic substances, (b) indoor and outdoor air pollution, (c) cigarette smoking (which complicates all studies of chronic disease), (d) radiation, with particular interest in low level effects and mechanisms of radiation carcinogenesis and mutagenesis, and (e) metals, chlorinated aromatic compounds and other chemicals of public health concern in industry or the general environment.